Spark plug



INVENTOR .l

ATToR Ys.

Nov. 26, 1935. n v Hf VINCENT n vSPARK PLUG Filed May l9, 1955 PatentedNov. 26, 1935 UNITED ,STATES PATENT FFI'CE SPARK PLUG Henri Vincent,Sucrerie de Kom-Omba, Egypt Application May 9, 1933, Serial No. 670,0615 Claims. (Cl. D23-169) This invention relates to a new and usefulimprovement in spark plug, the novel features of which will be bestunderstood from the following description and the annexed drawing, in4whichl I have shown a selected embodiment of the invention and in which:

Fig. 1 is an elevation of a spark plug constructed according to oneembodiment of the invention;

, Fig.`2 is a section on the line 2--2 of Fig. 1;

Fig. 3 is a bottom view of the structure appearing in Fig. 1; y

Figs. 4 and 5 are face views of the two electrodes.

By the use of the term spark plug herein, I intend to refer to a devicelocated in the wall of a combustion chamber and adapted to ignite gasestherein. Usually, as is well known in the art, such a device is made inthe form of a plug which can be readily removed and reinserted, althoughthe invention is not limited to that particular form of device. For thesake of convenience, however, I shall employ'the term "spark plug in thefollowing description and claims.

In Fig. 1, I have indicated at I a fragmentarypart of a wall of acombustion chamber having a threaded opening 2 therein in which may bethreaded a spark plug 3.` This plug may comprise an outer shell 4 ofmetallic or other`conductive material, within which'isdisposed a core 5of porcelain or other insulating material held in place in the shell bythe gland ii.

Extending longitudinally through the core 5 is a rod 1 of conductingmaterial having a cap 8 overlying the outer end of the core. This caphas a stem 9 upon which may be threaded'a nut I0, thus forming a bindingpost to which an electrical conductor may be secured. The shell isprovided with the usual wrench-engaging faces I2 and with threads I3 toengage corresponding threads on the wall of the opening 2.

'Ihe inner end of the plug, by which is meant the end within thecombustion chamber, is provided with two electrodes I4 and I5, and theseelectrodes extend a substantial distance beyond the inner end of theelectrode, which end I have designated I6. The electrode I4,'which ishere shown as the center electrode, is indicated as threaded intoengagement with the rod 'I, thereby forming a continuous path for theflow of an electric current from the binding post to the electrode,whereas the electrode I5 is shown as the side electrode threaded intoengagement with the shell Wall and thus forming a grounded connection,since the shell wall is threaded into engagement with the metallic wallI of the chamber.

The electrode I4 is shown as being of relatively massive constructionand having an extended flat surface II, this surface being disposed sothat it extends generally lengthwise of the plug but at 5 a slight angleto the axis thereof. The surface I'I faces the electrode I5, which maybe formed of a rod having its outer end I8 bent or arched inwardlytowards the center electrode and cut obliquely of its'length to form arelatively ex- 10 tended'surface I9, as best shown in Fig. 4. Thesurfaces Il and I9 are shown as being flat and substantially parallel toeach other and generally close together so that a spark may readily passbetween the two surfaces. The means for form- 15 ing the spark is, ofcourse, well understood in the art, and no description thereof isnecessary for an understanding of this invention.

I have found that, by use of the spark plug described above, thesparking is produced at a n0 point well Within the combustion chamber;it being noted in this connection that the surface I9 at the extreme endof the side electrode I5 is disposed adjacent the inner end 20 of theelectrode' I4, thus promoting rapid ignition of the 25 carburatedmixture and a consequent lessening of the time necessary for ignition.Moreover, the spark is produced away from the wall of the chamber andaway from any other point where there might be a collection of burnt orneutral gases, this again expediting starting of combustion within thechamber and consequently starting of the engine. y

Another result which I have found lto follow from the improvedconstruction is that, instead of producing a single spark, a group orshower of sparks is produced and, because of the inclined surface I1,this shower of sparks is directed toward the bottom or lowerend I 6ofthe plug,- thus tending to clean the plug and maintain it 40 clean. Ihave found that by the use of this plug,

I have been able to operate engines for extended periods of time withoutcausing the plugs to be clogged with carbon, grease, or other material,

in spite of the fact that a grade of fuel was being 45 used which wouldnormally cause this result to follow. The improved results I believe tobe caused at least in part by the features to which I have calledattention above. Whatever may be they explanation, the result is agreatly improved 50 one.

Whilev I have shown the invention as embodied in a specific form, it isto be understoodl that various changes in details may be made Withoutdeparting from the scope of the invention, and 55 I therefore do notintend to limit myself except by the' appended claims. y v I claim:

1. A spark plug comprising two electrodes extending lengthwise of theplug beyond the 'end thereof, one of said electrodes having an extendedsubstantially fiat surface disposed lengthwise of the plug and inclinedto the axis thereof, and the other electrode having a relatively smallsurface disposed adjacent said surface on the first-named electrode.

2. A spark plug comprising two electrodes extending lengthwise of theplug beyond the end thereof, one of said electrodes having an extendedsubstantially flat surface disposed lengthwise of the plug and inclinedto the axis thereof, and the other electrode having a relatively smallsurface disposed adjacentV said surface on the first-named electrode andparallel thereto.

3. A spark plug comprising two electrodes extending lengthwise of theplug beyond the end thereof, one of said 'electrodes having an extendedand substantially flat surface disposed lengthwise of the plug landinclined to the axis thereof, and the other electrode having arelativelysmall surface disposed adjacent said surfaceon the first-namedelectrode and adjacent the outer end thereof, at a location remote fromsaid end.

4. A spark plug comprising center and side electrodes extendinglengthwise .of the plug beyond the end thereof, the center electrodehaving an extended, elongated area with a substantially flat surfacedisposed lengthwise of the plug but at a small angle to the axisthereof, the side 'electrode having a relatively small area at its enddisposed adjacent the relatively large area of vthe center electrode anddisposed at a location wise of the plug and 'the other electrode havinga 20 relatively small substantially flat surface likewise disposedlengthwise of the plug and facing vsaid surface on the first-namedelectrode.

` HENRI VINCENT.

